Crossflow filtration system with quick dry change elements

ABSTRACT

A crossflow filtration system including at least one quick dry change crossflow filtration cartridge designed to rotatably interface with a manifold assembly. The quick dry change crossflow filtration cartridge can comprise a membrane element, for example an ultrafiltration membrane, microfiltration membrane, nanofiltration membrane or reverse osmosis membrane element enclosed within a housing. The quick dry change cartridge includes an inlet stream, a permeate stream and a concentrate stream. The manifold assembly includes three similar flow paths; an inlet stream, a permeate stream and a concentrate stream. When engaged, the cartridge and manifold assembly define continuous inlet flow paths, permeate flow paths and concentrate flow paths that connect across the interface. Thus, all of the connections to the water filtration system can be made onto the manifold, and the resulting connected system is compact and easy to connect.

RELATED APPLICATIONS AND PRIORITY CLAIM

[0001] The present invention claims priority to U.S. ProvisionalApplication No. 60/467,663, filed May 2, 2003 and entitled, “RESIDENTIALREVERSE OSMOSIS SYSTEM WITH QUICK DRY CHANGE ELEMENTS,” which is herebyincorporated by reference in its entirety.

FIELD OF THE INVENTION

[0002] The present invention relates generally to the field of waterfiltrations systems. More specifically, the present invention relates tocrossflow filtration systems utilizing a crossflow filtration elementcapable of being added and replaced by a quick connect attachment.

BACKGROUND OF THE INVENTION

[0003] Water filtration systems designed for use in the home are wellknown. Due to increasing concerns with regard to water quality, be itsupplied by a well or a municipality, the popularity of such systems hasincreased markedly. Some water filtration systems incorporate reverseosmosis filtration.

[0004] Typical reverse osmosis systems include a reverse osmosismembrane assembly, a pressure tank, a control element, a purified waterfaucet and a tubing/piping assembly defining the various flow paths. Ingeneral, an inlet water source is supplied to the membrane assemblywhere it is separated into a purified water stream (commonly referred toas permeate) and a concentrated waste stream (commonly referred to asconcentrate). The permeate may flow to a pressure tank where it cansubsequently be accessed through the pure water faucet. The concentrateis typically piped directly to drain. The control element working inconjunction with a series of valves in the tubing/piping assembly andthe pure water faucet generally operates the system and may includevarious monitoring sensors, for example conductivity/resistivity andflow sensors to insure the system is functioning properly.

SUMMARY OF THE INVENTION

[0005] The present invention comprises a crossflow filtration system,for example a residential crossflow filtration system, including atleast one quick dry change crossflow filtration cartridge designed torotatably interface with a manifold assembly. The quick dry changecrossflow filtration cartridge can comprise a membrane element, forexample an ultrafiltration membrane, microfiltration membrane,nanofiltration membrane or reverse osmosis membrane element enclosedwithin a housing. A rotatably engaging cartridge fastener has two matedelements with one element attached to the housing of the filtrationcartridge and the mated second element of the fastener attached to adocking port on the manifold. The housing includes a housing cap havingthe first fastener element for rotatably connecting to the mated secondfastening element at the docking port on the manifold assembly. Thefastener can comprise a variety of designs of mated elements, forexample, angled tabs, grooves, helical threads, multi-stage engagementmembers using threads and/or tabs and combinations thereof. Similarly,the mated second fastening element can comprise corresponding matedelements, such as angled tabs, grooves, ramps, multi-stage engagementmembers or combinations thereof, for interfacing with the first fastenerelement. The port on the manifold can also comprise a variety of capturemechanisms such that the cartridge fastener does not disengageunintentionally. Examples of appropriate rotatably engaging cartridgefasteners contemplated for use with the water purification systemsdescribed herein include, for example, those disclosed in U.S. patentapplication Ser. Nos. 09/618,686, 10/196,340, 10/202,290 and 10/406,637,all of which are hereby incorporated by reference in their entirety.

[0006] The quick dry change cartridge includes three flow paths withinthe housing and a crossflow filtration media element. The three flowpaths include an inlet stream, a permeate stream and a concentratestream. The manifold assembly includes three similar flow paths; aninlet stream, a permeate stream and a concentrate stream. When engaged,the cartridge and manifold assembly define continuous inlet flow paths,permeate flow paths and concentrate flow paths that connect across theinterface. Thus, all of the connections to the water filtration systemcan be made onto the manifold, and the resulting connected system iscompact and easy to connect. In contrast, reverse osmosis designs with aseparate condensate drain are represented by U.S. Pat. Nos. 3,746,640,4,391,712, 4,876,002, 5,122,265, 5,435,909, 5,527,450, 5,580,444 and6,436,282, all of which are hereby incorporated by reference in theirentirety.

[0007] When the filtering capacity of the crossflow filtration mediaelement is consumed, the unitary construction of the cartridge allowsfor quick and easy replacement with a new cartridge containing a newcrossflow filtration media element. As there is no disassembly of thecartridge filter, the replacement process can be accomplished withoutwater spillage. In addition, the time required is only that necessary torotatably remove a spent cartridge and rotatably install a newcartridge. Generally, disassembly and reassembly of the housing andfilter cartridge can be performed by hand without any tool, although atool can be used if desired. In certain embodiments, the filteringcharacteristics of the crossflow filtration system can be adjustablyvaried by replacing a cartridge filter having a first media with a newcartridge filter having a second type of filtration media. In addition,operational performance of the crossflow filtration system can beadjusted, which may be desired due to changes in the feedwaterchemistry, simply by replacing cartridge filters wherein the cartridgefilter includes a specific orifice, thereby controlling overall recoveryof the crossflow filtration system. Adjustment can be performed byvarying the backpressure on the concentrate stream, for example, byusing a flow restrictor such as an orifice or valve.

[0008] In a first aspect, the invention pertains to a crossflowfiltration system comprising a crossflow cartridge filter and amanifold. The crossflow cartridge filter can comprise a housing, anenclosed crossflow filtration media and a first fastener elementdefining three filter connections that are respectively in fluidcommunication with a filter feed channel, a filter permeate channel anda filter concentrate channel passing within the cartridge filter. Themanifold can comprise a second fastener element mated with the firstfastener element, the manifold having three manifold flow channels thatconnect respectively to three manifold connections on the secondfastener element. The three manifold connections connect on a one-to-onebasis with the three filter connections when the first fastener elementis engaged with the second fastener element.

[0009] In another aspect, the invention pertains to a crossflowfiltration filter comprising a filter housing, a crossflow filtrationelement and a filter cap. The crossflow filtration element can comprisea crossflow filtration media such as a microfiltration membrane, anultrafiltration membrane, a nanofiltration membrane or a reverse osmosismembrane. The filter cap can include channels for directing anddistributing a feed water stream, a concentrate stream and a permeatestream. The filter cap can further comprise engagement members allowingfor interconnection, for example rotatable engagement, with a filtermanifold.

[0010] In another aspect, the invention pertains to a crossflowfiltration manifold comprising a manifold body and a manifoldconnection. The manifold body and the manifold connection can define afeed flow channel, a permeate flow channel and the a concentrate flowchannel. The manifold connection can include an engagement member forallowing rotatable connection with a cartridge filter. The crossflowfiltration manifold can include a flow restriction, such as a valve ororifice, in the concentrate flow channel to backpressure and control thewater recovery for a crossflow filtration cartridge. The crossflowfiltration manifold can include a biased closed valve in the feed flowchannel to prevent water spillage when the manifold is not engaged witha cartridge filter. The crossflow filtration manifold can include acheck valve in the permeate flow channel to prevent backward flow offiltered water through the manifold.

[0011] In another aspect, the invention pertains to a method for forminga water filtration system with a crossflow filter. The method comprisesconnecting the crossflow filter to a manifold such a feed flow circuit,a permeate flow circuit and a concentrate flow circuit are formed andisolated by a crossflow filtration media.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012]FIG. 1 is a side view of a crossflow filtration assembly.

[0013]FIG. 2 is an exploded, perspective view of a crossflow cartridgefilter.

[0014]FIG. 3 is a sectional, side view of a filter housing.

[0015]FIG. 4 is a sectional, side view of a crossflow filtrationelement.

[0016]FIG. 5 is a sectional, side view of a filter dam.

[0017]FIG. 6 is a sectional, side view of a filter cap.

[0018]FIG. 7 is a top, end view of the filter cap of FIG. 6.

[0019]FIG. 8 is a bottom, end view of the filter cap of FIG. 6.

[0020]FIG. 9 is a sectional, side view of a crossflow cartridge filter.

[0021]FIG. 10 is an exploded, perspective view of a manifold assembly.

[0022]FIG. 11 is a perspective view of a distributing member.

[0023]FIG. 12 is a side view of a connecting member.

[0024]FIG. 13 is a perspective view of the connecting member of FIG. 12.

[0025]FIG. 14 is a sectional, side view of the connecting member of FIG.12.

[0026]FIG. 15 is a perspective, end view of the manifold assembly ofFIG. 10.

[0027]FIG. 16 is a side view of the manifold assembly of FIG. 10.

[0028]FIG. 17 is a sectional, side view of the manifold assembly of FIG.10 take along line A-A of FIG. 16.

[0029]FIG. 18 is a sectional, side view of the crossflow filtrationassembly of FIG. 1.

[0030]FIG. 19 is a schematic diagram of a water treatment systemincluding a crossflow filtration assembly.

[0031]FIG. 20 is an exploded, perspective view of an embodiment of awater treatment system.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0032] As illustrated in FIG. 1, an embodiment of a crossflow filtrationassembly 90 of the present invention comprises a manifold assembly 92and at least one crossflow cartridge filter 94. As depicted in FIG. 1,an embodiment of the crossflow filtration assembly 90 includes a supplytube 96, a concentrate tube 98 and a permeate tube 100.

[0033] The crossflow cartridge filter 94 is more clearly illustrated inFIG. 2. Generally, crossflow cartridge filter 94 comprises a filterhousing 108, a crossflow filtration element 110, a flow director 112 anda filter cap 114. Filter housing 108, flow director 112 and filter cap114 are constructed of suitable polymers for example, polypropylene orpolyethylene. Crossflow cartridge filter 94 is constructed so as to befixedly sealed and closed such that when replacement is necessary, theentire cartridge is replaced as opposed to replacing individualcartridge components such as crossflow filtration element 110. Thissystem has a single filter element. Different systems can incorporatedifferent numbers of filter elements, such as two, three, four or moreof the same or different types, as well as holding tanks. One particulardesign with multistage filtration is described further below.

[0034] As is shown in FIGS. 2 and 3, filter housing 108 comprises amolded polymeric structure having an open end 116 and a closed end 118.In some embodiments, filter housing 108 comprises a gripping element 120as shown in FIG. 2, for example a projecting surface, on closed end 118.Open end 116 can include an internal circumferential notch 122 topromote the interconnection and assembly of crossflow cartridge filter94. Filter housing 108 generally can have a smooth inner wall 124 andcan include an internal projection 126 protruding upward from theinternal surface of closed end 118, as shown in the cross-sectional viewof FIG. 3. Internal projection 126 can comprise a tapered guide surface128 for use during assembly of crossflow cartridge filter 94.

[0035] As depicted in FIG. 4, crossflow filtration element 110 cancomprise a spirally wound design referred to as a spiral wound element,in which a crossflow filter membrane media 130 is glued to and wrappedaround an interior permeate tube 132 having one or a plurality of tubebores 134. Permeate tube 132 has a cylindrical configuration includingan open tube end 136, a closed end 138 and a tube recess 140. At opentube end 136, permeate tube 132 includes a weld channel 142. A tuberecess 140 can be dimensioned to accommodate insertion of internalprojection 126 of filter housing 108 (FIG. 3) during assembly. Forpurposes of clarity, it is to be understood that the tube bores 134 arelocated between open end 136 and closed end 138.

[0036] In some embodiments, the crossflow filter membrane media 130 cancomprise two sheets of membrane, for example sheets of reverse osmosis,nanofiltration, ultrafiltration or microfiltration membrane, sandwichedover a spacer material. The two sheets of membrane can be glued aroundthree sides with a fourth side being open and glued to the permeate tube132 allowing water to be filtered through the individual flat sheets,into the spacer material, through the tube bores 134 and finally intopermeate tube 132. The crossflow filter membrane media 130 can bemanufactured of polymers such as cellulose acetate, polyamide andpolysulfone. Suitable crossflow filter membrane media 130 ismanufactured and sold by companies such as GE Water Technologies(formerly Osmonics, Inc.), Dow Liquid Separations/FilmTec, Hydranauticsand Koch Membrane Systems, among others. In alternative embodiments, thecrossflow filter membrane 130 can comprise tubular elements and/orsheets of membrane.

[0037] Flow director 112 depicted in FIGS. 2 and 5, comprises a mediaend 144, a cap end 146, a central throughbore 148 and a plurality ofperimeter throughbores 150. Central throughbore 148 and perimeterthroughbores 150 are isolated by interior wall 152. Media end 144 has acircular configuration with a diameter slightly greater than open end136 of interior permeate tube 132 such that a circumferential projectinglip 154 projects around the perimeter of crossflow filtration element110. Central throughbore 148 interfaces with media end 144 at aprojecting sealing surface 156. Projecting sealing surface 156 isdimensioned for insertion into open end 136 and includes a flangedsealing surface 158 having a circumferential weld energy director 160corresponding to weld channel 142 of interior permeate tube 132. Cap end146 is defined by end surfaces of an exterior wall 162, interior wall152 and a plurality of support ribs 164 shown in FIG. 2.

[0038] Filter cap 114 depicted in FIGS. 2, 6, 7 and 8 comprises amanifold engagement end 166, a cartridge sealing end 168, a plurality ofsupply throughbores 170, a central permeate throughbore 172 and aconcentrate bore 174. Permeate throughbore 172 is dimensioned toaccommodate the insertion of interior wall 152 of filter damn 112.Concentrate bore 174 is defined by an outlet portion 174 a and an inletportion 174 b. Outlet portion 174 a can comprise a precision drilled ormolded bore restriction. Alternatively, an orifice, for example adrilled orifice with an orifice filter, can be mounted within the outletportion 174 a to provide a desired cross-sectional opening with theoutlet portion 174 a. An interconnecting cavity 176 is exposed atmanifold engagement end 166 and includes a plurality of notches 178along a perimeter wall 180 of interconnecting cavity 176. Also withininterconnecting cavity 176 is a pair of arcuate interface ramps 182 a,182 b. A sealing cavity 184 is exposed at cartridge sealing end 168 andis dimensioned to accommodate flow director 112. Filter cap 114 includesan exterior surface 186 including a fastening element for connectingwith a mated fastening element on the assembly manifold 102. Thefastening element can comprise a pair of circumferential ramps 188 a,188 b, also depicted in FIG. 2. For interfacing with filter housing 108,the filter cap comprises a circumferential insertion lip 190, acircumferential recess 192 and a circumferential flange 194. While inthis embodiment filter damn 112 and filter cap 114 are separateelements, these elements can be formed as a single integral unit.

[0039] A sectional view of an assembled crossflow cartridge filter 94 isillustrated in FIG. 9. Flow director 112 is positioned with respect tocrossflow filtration element 110 such that the projecting sealingsurface 156 is slidingly inserted into the open tube end 136. Whenproperly positioned, weld energy director 160 at least partially resideswithin weld channel 142. Using a suitable welding process, for examplespin welding or ultrasonic welding, the weld energy director 160 andweld channel 142 can be attached. At the same time, projecting lip 154can be sealed by friction bonding and/or the use of a suitable adhesiveabout the outside of crossflow filtration element 110. Crossflowfiltration element 110 is directed into the open end 116 of filterhousing 108 such that the internal projection 126 is inserted into thetube recess 140. Filter cap 114 is positioned and directed such that thecartridge sealing end 168 is proximal the cap end 146 and the open end116, causing slidable insertion of the interior wall 152 into thecentral permeate throughbore 172. Simultaneously, the circumferentialinsertion lip 190, circumferential recess 192 and the circumferentialflange 194 contact the filter housing 108, for example at internalcircumferential notch 122. Using a suitable welding process, for examplespin welding or ultrasonic welding, filter cap 114 is welded to filterhousing 108 to form the completed crossflow cartridge filter 94.Suitable adhesive sealing methods can also be employed during theassembly of crossflow cartridge filter 94 in addition or as analternative to a welding process.

[0040] When assembled, crossflow cartridge filter 94 defines threedistinct flow circuits: a feed water flow circuit, a permeate flowcircuit and a concentrate flow circuit. Incoming feed water enters thefeed water flow circuit through the supply throughbores 170 such thatthe feed water flows through the filter cap 114. The feed water thenpasses through the perimeter throughbores 150 on the flow director 112and into crossflow filtration element 110. As the feed water passesacross the crossflow filter membrane media 130, purified water entersthe permeate flow circuit through the tube bores 134 in the interiorpermeate tube 132. The permeate flow circuit is defined by the interiorpermeate tube 132, the central throughbore 148 on the flow director 112and the central permeate throughbore 172 on filter dam 114. Any waterthat passes across crossflow filtration element 110 without entering thepermeate flow circuit flows out the bottom of the crossflow filtrationelement 110 and into the concentrate flow circuit. The concentrate flowcircuit is first defined by the gap between the exterior of thecrossflow filtration element 110 and the smooth inner wall 124. Theconcentrate fluid circuit is further defined by the concentrate bore 174whereby concentrate is collected and distributed out of the crossflowcartridge filter 94.

[0041] As illustrated in FIG. 10, an embodiment of manifold assembly 92can comprise a distributing member 196, a connecting member 198, aspring loaded valve 200, a pair of first O-ring seals 202 a, 202 b and apair of second O-ring seals 204 a, 204 b.

[0042] Distributing member 196 is illustrated in FIGS. 10 and 11.Distributing member 196 has a distribution end 206 and a connection end208. Extending between the distribution end 206 and the connection end208 are a distribution feed throughbore 210, a distribution concentratethroughbore 212 and a distribution permeate throughbore 214. Located onconnection end 208 is a pair of attachment projections 216. Connectionend 208 further includes a connecting surface 218 and a perimeterdistribution wall 220. Perimeter distribution wall 220 includes a filterreceiving means, shown as a pair of tabs 222 a, 222 b and a pair ofsloped members 224 a, 224 b.

[0043] Connecting member 198, as shown in FIGS. 12, 13 and 14, includesa manifold attachment end 226 and a filter attachment end 228. Manifoldattachment end 226 includes a feed inlet bore 230, a permeate outletbore 232 and a concentrate outlet bore 234. Manifold attachment end 226further includes a pair of manifold attachment members 236 forinterconnection of the connecting member 198 to the distributing member196. Filter attachment end 228 includes a connector projection 238 witha permeate throughbore 240 in fluid connection with the permeate outletbore 232. Filter attachment end 228 further includes a feed outlet bore241. Connector projection 238 has a pair of circumferential projectiongrooves 242 a, 242 b for receiving the O-ring seals 202 a, 202 b.Connector projection 238 has a diameter such that connector projection238 inserts into the central permeate throughbore 172. Connecting member198 includes a pair of circumferential body grooves 246 a, 246 b forreceiving O-ring seals 204 a, 204 b. Located between circumferentialbody grooves 246 a, 246 b is a concentrate inlet bore 250.

[0044] Manifold assembly 92 is generally constructed as shown in FIGS.10, 15, 16 and 17. Distributing member 196 is oriented such that theconnection end 208 is facing the manifold attachment end of theconnecting member 198. The spring loaded valve 200 is positioned suchthat it is captured and resides on a valve seat 251 within thedistribution feed throughbore 210 and the feed inlet bore 230 as thedistributing member 196 and the connecting member 198 are coupled. Asthe distributing member 196 and the connecting member 198 come intocontact, the manifold attachment members 236 slide over the attachmentprojections 216. Once the connection end 208 and the manifold attachmentend 226 are in physical contact, the distributing member 196 and theconnecting member 198 are joined with a suitable joining technique, forexample sonic welding and/or adhesive bonding. When the distributingmember 196 and the connecting member 198 are operably joined, acontinuous manifold feed channel 252 is defined by the distribution feedthroughbore 210, the feed inlet bore 230 and the feed outlet bore 241; acontinuous manifold concentrate channel 254 is defined by theconcentrate inlet bore 250, the concentrate outlet bore 234 and thedistribution concentrate throughbore 212; and a continuous manifoldpermeate channel 256 is defined by the permeate throughbore 240, thepermeate outlet bore 232 and the distribution permeate throughbore 214.In alternative embodiments, the distribution member and the connectionmember can be formed as a single integral unit.

[0045] Following the assembly and plumbing of manifold assembly 92, thecrossflow cartridge filter 94 is sealingly attached to the manifoldassembly 92 as shown in FIG. 18. In one embodiment, the crossflowcartridge filter 94 is rotatably coupled to the manifold assembly 92.Crossflow cartridge filter 94 is positioned and aligned such thatcentral throughbore 148 is in alignment with and proximate to connectorprojection 238. Connector projection 238 is slidably inserted intocentral throughbore 148 such that circumferential ramps 188 a, 188 bphysically contact tabs 222 a, 222 b. Crossflow cartridge filter 94 isrotatably biased such that circumferential ramp 188 a is capturedbetween tab 222 a and sloped member 224 a while circumferential ramp 188b is simultaneously captured between tab 222 b and sloped member 224 b.Further rotation of crossflow cartridge filter 94 causes approximationof the crossflow cartridge filter 94 and the manifold assembly 92 suchthat connector projection 238 is fully inserted into central throughbore148. Ultimately, the first pair of O-ring seals 202 a, 202 b create afluid tight seal between connector projection 238 and centralthroughbore 148 to prevent water leakage. As connector projection 238 isfully inserted into central throughbore 148, either arcuate interfaceramp 182 a or 182 b contacts the spring loaded valve 200. As crossflowcartridge filter 94 is rotated, arcuate interface ramp 182 a or 182 bcauses spring loaded valve 200 to compress such that the spring loadedvalve 200 is lifted from the valve seat 251. As spring loaded valve 200is lifted from valve seat 251, feed water can begin to flow into themanifold assembly 92.

[0046] Once the crossflow filtration assembly 90 is assembled, feedwater can begin to flow into the manifold assembly 92 through the supplytube 96. The feed water flows past the spring loaded valve 200 withinthe manifold feed channel 252 and enters the crossflow cartridge filter94 through the supply throughbores 170. The feed water enters thecrossflow filtration element 110 such that some water is directedthrough the membrane media 130. As the water travels the length ofcrossflow filtration element 110, the water volume decreases while thenumber of contaminants present within the water flow increases. At theend of the crossflow filtration element 100 nearest the closed end 118,the concentrated feed water flows from the crossflow filtration element110 to form a concentrate stream having a high concentration ofcontaminants. At the same time, purified water that has passed throughthe membrane media 130 is collected within the interior permeate tube132 to form a permeate stream, essentially free of contaminants.

[0047] The concentrate stream flows between the crossflow filtrationelement 110 and the inner wall 124. By directing the concentrate streamin the gap between the crossflow filtration element 110 and the innerwall 124, the potential for deadspots or regions of stagnant water iseliminated. By eliminating deadspots, the potential for biologicalgrowth and contamination within the crossflow filtration element 110 isminimized. The concentrate stream enters the circumferential concentratebore 174 whereby the concentrate stream flows into the concentrate inletbore 250. O-ring seals 204 a, 204 b prevent the concentrate stream fromcontaminating either the feed stream or the permeate stream. From theconcentrate inlet bore 250, the concentrate stream is directed throughthe manifold concentrate channel 254 and to drain through theconcentrate tube 98. At various points, either within the manifoldassembly 92 or the crossflow cartridge filter 94, a restriction can beplaced within the concentrate flow stream to backpressure theconcentrate stream such that the volume of the permeate stream can beincreased or decreased. For example, this restriction can take the formof a fixed or adjustable orifice located in first portion 174 a, or avalve within the manifold assembly 92. The restriction is typicallyadjusted based on the water quality of the feed supply. For a highquality feed supply, the volume of the permeate stream can be increasedas opposed to a feed water supply of a lower quality. For example, wherethe feed supply is of a poor quality, the recovery can be set at 50%wherein half of the incoming feed supply is filtered to become thepermeate stream. Where the feed supply is of a high quality, therecovery can be set as high at 90% wherein the flow rate of the permeatestream is 90% of the flow rate of the feed supply.

[0048] The purified permeate stream is collected within the interiorpermeate tube 132 whereby it flows through the central throughbore 148and into the permeate throughbore 240. Once in the permeate throughbore240, the permeate stream flows through the manifold permeate channel 256whereby the permeate stream is directed to points of use by the permeatetube 100. In an embodiment, permeate tube 100 may deliver the permeatestream to a pressurized permeate tank for subsequent distribution topoints of use. In the case of a pressurized permeate tank, the manifoldassembly 92 could include a checkvalve to prevent any backflow ofpermeate from the pressurized permeate tank when the crossflow cartridgefilter 94 is removed from the manifold assembly 92.

[0049] As illustrated in FIG. 19, crossflow filtration assembly 90 canbe used in conjunction with a pretreatment filter 300 and aposttreatment filter 302 to form a water treatment system 304. Asillustrated, water treatment system 304 can further comprise a feedinlet 306, a pretreatment manifold 308, a shutoff valve 310, acheckvalve 312, a flow restrictor 314, a drain 316, a permeate outlet317, a storage tank 318, a posttreatment manifold 320, distributionstream 321 and a distribution control 322. The water treatment system304 can be selectively configured, through the use of variouspretreatment filters 300 and posttreatment filters 302 to provide adesired filtered water quality based upon the available feed waterquality. For instance, pretreatment filter 300 can include a filtermedia to remove particulate matter, chlorine, chloramines, organics orhardness. Likewise, posttreatment filter 302 can include filter media toremove any remaining dissolved solids, chlorine, organics and biologicalmaterial or to removed undesirable taste and/or odor associated withwater stored in storage tank 318. Furthermore, pretreatment filter 308can be configured to increase the permeate recovery of the crossflowfiltration assembly 90 such that the flow rate to drain 316 is reduced.The flow restrictor can be used to alter the performance of thefiltration medium. In particular, a more restricting flow restrictor canbe used to lower the ratio of concentrate flow to permeate flow, while aless restricting flow restrictor increases the ratio of concentrate flowto permeate flow.

[0050] In one alternative embodiment of water treatment system 304illustrated in FIG. 20, crossflow filtration assembly 90, pretreatmentfilter 300, posttreatment filter 302, feed inlet 306, pretreatmentmanifold 308, shutoff valve 310, checkvalve 312, flow restrictor 314,drain 316, posttreatment manifold 320 and distribution stream 321 can beincorporated into a unitary manifold assembly 330. Both pretreatmentfilter 300 and pretreatment manifold 308 as well as posttreatment filter302 and posttreatment manifold 320 can make use of quick connect filterand manifold assembly designs having one inlet and one outlet, forexample as disclosed in U.S. patent applications Ser. Nos. 09/618,686,10/196,340, 10/202,290 and 10/406,637.

[0051] Although various embodiments of the present invention have beendisclosed here for purposes of illustration, it should be understoodthat a variety of changes, modifications and substitutions might beincorporated without departing from either the spirit or scope of thepresent invention.

What is claimed:
 1. A crossflow filtration system comprising: acrossflow cartridge filter comprising a housing, an enclosed crossflowfiltration media and a first fastener element defining three filterconnections that are respectively in fluid communication with a filterfeed channel, a filter permeate channel and a filter concentrate channelpassing within the cartridge filter; and a manifold comprising a secondfastener element mated with the first fastener element, the manifoldhaving three manifold flow channels that connect respectively to threemanifold connections on the second fastener element, wherein the threemanifold connections connect on a one-to-one basis with the three filterconnections when the first fastener element is engaged with the secondfastener element.
 2. The crossflow filtration system of claim 1, whereinthe enclosed crossflow filtration media comprises an ultrafiltrationmembrane, a microfiltration membrane, a nanofiltration membrane or areverse osmosis membrane.
 3. The crossflow filtration system of claim 1,wherein the first fastener element is rotatably engageable with thesecond fastener element to operably couple the cartridge filter and themanifold.
 4. The crossflow filtration system of claim 1, wherein themanifold further comprises a prefilter fastener element for mounting aprefilter cartridge such that a feedwater source is prefiltered prior toentering the crossflow cartridge filter.
 5. The crossflow filtrationsystem of claim 1, wherein the manifold further comprises a postfilterfastener element for mount a postfilter cartridge such that a filteredwater stream is postfiltered prior to being distributed to a point ofuse.
 6. A crossflow filtration filter comprising: a filter housinghaving a first end and a second end; a crossflow filtration elementwithin the filter housing; and a filter cap having a feed bore, apermeate bore and a concentrate bore, wherein the filter cap is attachedat the first end such that the crossflow filtration element is retainedwithin the filter housing, and wherein the filter cap, the filterhousing and the crossflow filtration element cooperatively define andisolate a feed channel, a permeate channel and a concentrate channel,respectively in fluid communication with the feed bore, the permeatebore, and the concentrate bore.
 7. The crossflow filtration filter ofclaim 6, wherein the filter cap has a filter connection such that thecrossflow filtration filter is rotatably engageable to a manifoldassembly.
 8. The crossflow filtration filter of claim 6, wherein thecrossflow filtration filter has an ultrafiltration membrane, amicrofiltration membrane, a nanofiltration membrane or a reverse osmosismembrane.
 9. The crossflow filtration filter of claim 6, wherein theconcentrate bore includes a flow restriction to control backpressure ofa concentrate stream to maintain a desired permeate recovery.
 10. Acrossflow filtration manifold comprising: a manifold body having a feedflow channel, a permeate flow channel and a concentrate flow channel,and a manifold connection comprising a fastener element with a feedconnection, a permeate connection and a concentrate connection isolatedfrom each other and in fluid communication respectively with the feedflow channel, the permeate flow channel and the concentrate flowchannel.
 11. The crossflow filtration manifold of claim 10, wherein thefeed flow channel includes a biased closed valve such that a feed supplyflows through the manifold only when a crossflow filter is engaged withthe manifold connection.
 12. The crossflow filtration manifold of claim10, wherein the manifold connection is rotatably engaged with thecrossflow filter.
 13. The crossflow filtration manifold of claim 10,wherein the permeate flow channel includes a checkvalve such that apermeate stream is prevented from flowing in a reverse direction throughthe manifold.
 14. The crossflow filtration manifold of claim 10, whereinthe concentrate flow channel includes a flow restriction to controlbackpressure of a concentrate stream to maintain a desired permeaterecovery.
 15. The crossflow filtration manifold of claim 14, wherein theflow restriction comprises a valve or an orifice.
 16. The crossflowfiltration manifold of claim 14, wherein the flow restriction isadjustable such that the permeate recovery can be adjusted based on adesired recovery level or a feed supply quality.
 17. The crossflowfiltration manifold of claim 9, wherein the concentrate connection issealingly isolated from the feed flow channel by at least one sealingmember.
 18. The crossflow filtration manifold of claim 17, wherein theat least one sealing member is an O-ring seal.
 19. A method for forminga water filtration system with a crossflow filter, the methodcomprising: connecting a cartridge filter to a manifold, the cartridgefilter having a first fastener element and the manifold assembly havinga second fastener element wherein attaching the first fastener elementand the second fastener element completes a feed flow circuit, apermeate flow circuit and a concentrate flow circuit between thecartridge filter and the manifold wherein the respective flow circuitsare isolated from each other by a crossflow filter media.
 20. The methodof claim 19, wherein the first fastener element and the second fastenerelement are rotatably connected to complete the feed flow circuit, thepermeate flow circuit and the concentrate flow circuit.
 21. The methodof claim 19, wherein the crossflow media is an ultrafiltration membrane,a microfiltration membrane, a nanofiltration membrane or a reverseosmosis membrane.